Search Results (64)

Soil degradation and water scarcity pose major challenges to sustainable agriculture in semiarid regions, requiring innovative strategies to enhance water use efficiency (WUE) and soil fertility. This study assessed the effects of sewage sludge biochar (SSB) on soil properties, WUE, and common bean yield through a small-scale controlled field experiment under rainfed conditions in Northeast Brazil. Four SSB application rates (5, 10, 20, and 40 t ha⁻¹) were compared with conventional NPK fertilization, treated sewage sludge (SS), and chicken manure (CM). The application of 20 t ha⁻¹ (B20) significantly improved soil organic carbon, nitrogen content, water retention, and microbial biomass. B20 also increased WUE by 148% and grain yield by 146% relative to NPK, while maintaining safe levels of potentially toxic elements (PTE) in bean grains. Although 40 t ha⁻¹ (B40) enhanced soil fertility further, it posed a risk of PTE accumulation, reinforcing the advantage of B20 as an optimal and safe dose. These results highlight the potential of SSB to replace or complement conventional fertilizers, especially in sandy soils with limited water retention. The study supports SSB application as a sustainable soil management practice that aligns with circular economy principles, offering a viable solution for improving productivity and environmental resilience in semiarid agriculture. Full article

This study presents a bibliometric review aimed at mapping and analyzing the scientific literature related to the ethical implications of artificial intelligence (AI) in livestock farming, which is a rapidly emerging yet still underexplored field in international research. Based on the Scopus database, 151 documents published between 2015 and 2025 were identified and analyzed using the VOSviewer version 1.6.20 and Biblioshiny for Bibliometrix (RStudio version 2023.12.1) tools. The results show a significant increase in publications from 2021 onwards, reflecting the growing maturity of discussions around the integration of digital technologies in the agricultural sector. Keyword co-occurrence and bibliographic coupling analyses revealed the formation of four main thematic clusters, covering technical applications in precision livestock farming as well as reflections on governance, animal welfare, and algorithmic justice. The most influential authors, high-impact journals, and leading countries in the field were also identified. As a key contribution, this study highlights the lack of robust ethical guidelines and proposes future research directions for the development of regulatory frameworks, codes of conduct, and interdisciplinary approaches. The findings underscore the importance of aligning technological innovation with ethical responsibility and social inclusion in the transition to digital livestock farming. Full article

The Oropouche virus (OROV) is an arbovirus (Peribunyaviridae: Orthobunyavirus) that traditionally causes febrile outbreaks in Latin America’s Amazon region. Previously, OROV was not associated with severe pregnancy outcomes. During the 2022–2024 outbreak in Brazil, OROV expanded geographically, revealing links to adverse pregnancy outcomes. This study describes six cases with varied fetal outcomes, including miscarriage, antepartum, intrauterine fetal demise (IFD), and normal development, correlating with maternal symptoms but not symptom severity. Vertical transmission was confirmed by detecting OROV through RT-qPCR, ELISA, and immunohistochemistry in fetal tissues. Genome sequencing from an IFD case identified a novel reassortment pattern reported in the 2022–2024 outbreak. Severe encephalomalacia, meningoencephalitis, vascular compromise, and multi-organ damage were evident, underscoring the significant risk OROV poses to fetal development and emphasizing the need for further investigation. Full article

This study aimed to characterize and evaluate the fibrinolytic, thrombolytic, hematological, and toxicological aspects of a serine protease (AsKSP) from Aspergillus tamarii Kita UCP 1279. The enzyme was purified using a two-phase aqueous system and assessed for optimal pH (7.0) and temperature (50 °C), stability, and effects of metal ions, inhibitors, and surfactants. AsKSP exhibited stability for up to 120 min at 50 °C and 36 h at pH 7.0. Enzymatic activity was enhanced by Na⁺ and Zn²⁺ and non-ionic surfactants (Tween-80) but inhibited by Cu²⁺, Fe³⁺, Triton X-100, and SDS, reducing activity by up to 62.35%. The highest amidolytic activity was observed for the substrate N-succinyl-Gly–Gly–Phe-p-nitroanilide. SDS-PAGE analysis indicated an approximate molecular mass of 90 kDa. The enzyme showed fibrinolytic activity, degrading 38.81% of fibrin clots in vitro after 90 min, without affecting fibrinogen. Cytotoxicity assays indicated no toxicity (cell viability > 80%). Coagulation assays showed slight prolongation of prothrombin time (PT) and activated partial thromboplastin time (aPTT), with no effect on thrombin time. No red blood cell lysis was observed, and albumin increased enzymatic activity by 31.70%. These findings demonstrate that Aspergillus tamarii Kita UCP 1279 produces a fibrinolytic protease with potential for thrombus treatment, providing a promising foundation for drug development. Full article

Anacardium occidentale, known as cashew tree, is widely used in the Amazon. This study aimed to evaluate the chemical composition, as well as the biological, physicochemical, antioxidant, and acceptability properties, of the essential oil (EO) extracted from the leaves of the dwarf cashew tree (EOLC) from the Amazonian savanna. The EO was obtained by hydrodistillation from fresh and frozen leaves, with the frozen sample selected due to its higher yield. The components of the EOLC were identified by GC-MS. Antioxidant activity was assessed using DPPH and ABTS radicals, with values of 1.96 µmol Trolox mL⁻¹ and 1.41 mM, respectively. Total phenolic content was determined by the Folin–Ciocalteu method. Antibacterial activity was evaluated by agar diffusion and minimum inhibitory concentration (MIC) methods, and toxicity was assessed with Artemia salina L. The physicochemical properties analyzed included density, refractive index, viscosity, and solubility. Terpinolene was identified as the major compound (80.21%). The EOLC exhibited antioxidant capacity, stronger antibacterial action against Gram-positive bacteria, moderate toxicity, and appropriate physicochemical characteristics. The 0.05% concentration was the most accepted in the sensory evaluation, standing out as a promising natural alternative for application in meat products. These findings highlight the potential of EOLC as a natural food preservative and a source of bioactive compounds, with promising applications in various food matrices. Full article

Reducing losses during pig transport is essential for breeders and transporters, particularly in semi-arid regions, where high temperatures exacerbate transport-related stress and risk of losses. This study aimed to evaluate the effect of transport duration (short vs. long trips) on animal welfare and production losses during the commercial transport of weaner pigs in a semi-arid region. A total of 20 commercial journeys were monitored, with transport times of 30 min (15 km) and 150 min (170 km). Upon arrival, physiological and behavioral stress indicators were assessed in 960 weaner pigs (26.4 ± 2.8 kg body weight, 48 per journey). Production losses were determined by calculating the percentage of injured pigs (NAI), fatigued pigs (NANI), and those that were dead on arrival (DOA), whereas the total loss was expressed by the sum of NAI + NANI + DOA. Weaner pigs transported for 30 min exhibited significantly higher (p < 0.05) rectal temperature, respiratory rate, and stress biomarkers (cortisol and creatine kinase levels). Additionally, this group showed a higher percentage (p < 0.05) of “sitting” pigs and a lower percentage of “lying” pigs in transit, as well as a higher frequency of agonistic behavior after transport compared to those transported for 150 min. Furthermore, higher production losses were recorded in the 30 min transport group, primarily due to the increased percentage of fatigued pigs and DOA pigs. Therefore, shorter transport operations in the Brazilian semi-arid region increased the risk to animal welfare and productive losses, likely due to handling-induced stress during loading. Full article

Selene-ethylenelacticamide derivatives have been suggested as promising scaffolds with leishmanicidal activity. In this work, we demonstrated, for the first time, the effectiveness of selene-ethylenelacticamide derivatives against mycobacteria. Firstly, selene-ethylenelacticamides inhibited the growth of laboratory strains of Mycobacterium tuberculosis with MIC values ranging from 10 to 20 µM. Importantly, three derivatives were active against two multi-drug-resistant clinical isolates of M. tuberculosis with MIC values similar to pan-sensitive strains. In addition, NC31 and NC34 displayed an improved activity compared to the group treated with isoniazid in the six-week nutrient-starved M. tuberculosis cultures. Moreover, in toxicity studies, NC34 did not significantly affect the viability of both Vero E6 and HepG2 cell lines. NC34 did not affect Artemia salina nauplii survival at concentrations lower than 100 µM. Importantly, NC34 displayed a synergistic effect when combined with rifampicin. Molecular docking simulations were used to evaluate Mycobacterium tuberculosis DprE1 and dihydrofolate reductase enzymes as putative targets of selene-ethylenelacticamides, mechanisms that could contribute to the antitubercular activity. Our findings reveal that NC34 may represent a hit for further drug optimization and for future preclinical development as a new anti-mycobacterial agent, especially in cases of resistant and/or dormant forms of tuberculosis. Full article

Background: Phytol is a diterpene from the long-chain unsaturated acyclic alcohols, known for its diverse biological effects, including antimicrobial and anti-inflammatory activities. Present in essential oils, phytol is a promising candidate for various applications in the pharmaceutical and biotechnological sectors. This study aimed to evaluate the in vitro antibacterial and drug-potentiating effects of phytol against multidrug-resistant bacteria and to evaluate its in silico properties: ADME and molecular docking. Methods: The in vitro antibacterial activity of phytol and the phytol combined with conventional drugs was evaluated by microdilution tests against standard and resistant bacterial strains. Finally, the SwissADME platform was employed to analyse the physicochemical and pharmacokinetic characteristics of phytol. Results: Phytol significantly reduced the Minimum Inhibitory Concentration (MIC) of norfloxacin and gentamicin required to inhibit multidrug-resistant strains of Escherichia coli and Staphylococcus aureus, respectively. Additionally, ADME analysis revealed that phytol exhibits low toxicity and favourable pharmacokinetic properties; in addition, it is revealed through molecular docking that phytol showed a relevant affinity with the proteins 6GJ1 and 5KDR, however, with values lower than the drugs gentamicin and ampicillin. Conclusions: Collectively, these findings suggest that phytol holds potential as an effective adjuvant in combating antimicrobial resistance. Full article

Marine organisms represent a potential source of secondary metabolites with various therapeutic properties. However, the pharmaceutical industry still needs to explore the algological resource. The species Caulerpa lamouroux Forssk presents confirmed biological activities associated with its major compound caulerpin, such as antinociceptive, spasmolytic, antiviral, antimicrobial, insecticidal, and cytotoxic. Considering that caulerpin is still limited, such as low solubility or chemical instability, it was subjected to a structural modifications test to establish which molecular regions could accept structural modification and to elucidate the cytotoxic bioactive structure in Vero cells (African green monkey kidney cells, Cercopithecus aethiops; ATCC, Manassas, VA, USA) and antiviral to Herpes simplex virus type 1. Substitution reactions in the N-indolic position with mono- and di-substituted alkyl, benzyl, allyl, propargyl, and ethyl acetate groups were performed, in addition to conversion to their acidic derivatives. The obtained analogs were submitted to cytotoxicity and antiviral activity screening against Herpes simplex virus type 1 by the tetrazolium microculture method. From the semi-synthesis, 14 analogs were obtained, and 12 are new. The cytotoxicity assay showed that caulerpin acid and N-ethyl-substituted acid presented cytotoxic concentrations referring to 50% of the maximum effect of 1035.0 µM and 1004.0 µM, respectively, values significantly higher than caulerpin. The antiviral screening of the analogs revealed that the N-substituted acids with methyl and ethyl groups inhibited Herpes simplex virus type 1-induced cytotoxicity by levels similar to the positive control acyclovir. Full article

In 2019, the emergence of the seventh known coronavirus to cause severe illness in humans triggered a global effort towards the development of new drugs and vaccines for the SARS-CoV-2 virus. These efforts are still ongoing in 2024, including the present work where we conducted a ligand-based virtual screening of terpenes with potential anti-SARS-CoV-2 activity. We constructed a Quantitative Structure–Activity Relationship (QSAR) model from compounds with known activity against SARS-CoV-2 with a model accuracy of 0.71. We utilized this model to predict the activity of a series of 217 terpenes isolated from the Fabaceae family. Four compounds, predominantly triterpenoids from the lupane series, were subjected to an in vitro phenotypic screening in Vero CCL-81 cells to assess their inhibitory activity against SARS-CoV-2. The compounds which showed high rates of SARS-CoV-2 inhibition along with substantial cell viability underwent molecular docking at the SARS-CoV-2 main protease, papain-like protease, spike protein and RNA-dependent RNA polymerase. Overall, virtual screening through our QSAR model successfully identified compounds with the highest probability of activity, as validated using the in vitro study. This confirms the potential of the identified triterpenoids as promising candidates for anti-SARS-CoV-2 therapeutics. Full article

Massive vaccination positively impacted the SARS-CoV-2 pandemic, being a strategy to increase the titers of neutralizing antibodies (NAbs) in the population. Assessing NAb levels and understanding the kinetics of NAb responses is critical for evaluating immune protection. In this study, we optimized and validated a PRNT₅₀ assay to assess 50% virus neutralization and evaluated its accuracy to measure NAbs to the original strain or variant of SARS-CoV-2. The optimal settings were selected, such as the cell (2 × 10⁵ cells/well) and CMC (1.5%) concentrations and the viral input (~60 PFU/well) for PRNT-SARS-CoV-2 with cut-off point = 1.64 log₅ based on the ROC curve (AUC = 0.999). The validated PRNT-SARS-CoV-2 assay presented high accuracy with an intraassay precision of 100% for testing samples with different NAb levels (low, medium, and high titers). The method displays high selectivity without cross-reactivity with dengue (DENV), measles (MV), zika (ZIKV), and yellow fever (YFV) viruses. In addition, the standardized PRNT-SARS-CoV-2 assay presented robustness when submitted to controlled variations. The validated PRNT assay was employed to test over 1000 specimens from subjects with positive or negative diagnoses for SARS-CoV-2 infection. Patients with severe COVID-19 exhibited higher levels of NAbs than those presenting mild symptoms for both the Wuhan strain and Omicron. In conclusion, this study provides a detailed description of an optimized and validated PRNT₅₀ assay to monitor immune protection and to subsidize surveillance policies applied to epidemiologic studies of COVID-19. Full article

Acute myocardial infarction (AMI) is the main cause of morbidity and mortality worldwide and is characterized by severe and fatal arrhythmias induced by cardiac ischemia/reperfusion (CIR). However, the molecular mechanisms involved in these arrhythmias are still little understood. To investigate the cardioprotective role of the cardiac Ca²⁺/cAMP/adenosine signaling pathway in AMI, L-type Ca²⁺ channels (LTCC) were blocked with either nifedipine (NIF) or verapamil (VER), with or without A₁-adenosine (ADO), receptors (A₁R), antagonist (DPCPX), or cAMP efflux blocker probenecid (PROB), and the incidence of ventricular arrhythmias (VA), atrioventricular block (AVB), and lethality (LET) induced by CIR in rats was evaluated. VA, AVB and LET incidences were evaluated by ECG analysis and compared between control (CIR group) and intravenously treated 5 min before CIR with NIF 1, 10, and 30 mg/kg and VER 1 mg/kg in the presence or absence of PROB 100 mg/kg or DPCPX 100 µg/kg. The serum levels of cardiac injury biomarkers total creatine kinase (CK) and CK-MB were quantified. Both NIF and VER treatment were able to attenuate cardiac arrhythmias caused by CIR; however, these antiarrhythmic effects were abolished by pretreatment with PROB and DPCPX. The total serum CK and CK-MB were similar in all groups. These results indicate that the pharmacological modulation of Ca²⁺/cAMP/ADO in cardiac cells by means of attenuation of Ca²⁺ influx via LTCC and the activation of A₁R by endogenous ADO could be a promising therapeutic strategy to reduce the incidence of severe and fatal arrhythmias caused by AMI in humans. Full article

Major depressive disorder is a severe mood disorder characterized by different emotions and feelings. This study investigated the antidepressant activity of the phenylpropanoid methyleugenol (ME) in adult female mice exposed to a stress model induced by dexamethasone. The animals were randomly divided into groups containing eight animals and were pre-administered with dexamethasone (64 μg/kg subcutaneously). After 165 and 180 min, they were treated with ME (25, 50 and 100 mg/kg intraperitoneally) or imipramine (10 mg/kg intraperitoneally) after 45 min and 30 min, respectively; they were then submitted to tests which were filmed. The videos were analyzed blindly. In the tail suspension test, ME (50 mg/kg) increased latency and reduced immobility time. In the splash test, ME (50 mg/kg) decreased grooming latency and increased grooming time. In the open field, there was no statistical difference for the ME groups regarding the number of crosses, and ME (50 mg/kg) increased the number of rearing and time spent in the center. Regarding in silico studies, ME interacted with dopaminergic D1 and α1 adrenergic pathway receptors and with tryptophan hydroxylase inhibitor. In the in vivo evaluation of the pathways of action, the antidepressant potential of ME (50 mg/kg) was reversed by SCH23390 (4 mg/kg intraperitoneally) dopaminergic D1 receptor, Prazosin (1 mg/kg intraperitoneally) α1 adrenergic receptor, and PCPA (4 mg/kg intraperitoneally) tryptophan hydroxylase inhibitor. Our findings indicate that ME did not alter with the locomotor activity of the animals and shows antidepressant activity in female mice with the participation of the D1, α1 and serotonergic systems. Full article

Dengue, Chikungunya and Zika are arboviruses, transmitted by the mosquito Aedes aegypti, that cause high mortality and serious health consequences in human populations. Efforts to control Ae. aegypti are important for preventing outbreaks of these diseases. Essential oil constituents are known to exhibit many activities, such as their use as larvicides. Given their potential, the present study aimed to characterize the larvicidal effect of dihydrojasmone, p-cymene, carvacrol, thymol, farnesol and nerolidol on the larvae of Ae. aegypti and their interference over the morphology of the mosquitos. The essential oil constituents were dissolved in dimethylsulfoxide at concentrations of 1–100 μg/mL and were applied in the breeding environment of third-stage larvae. The larvae from bioassays were fixed, dehydrated and embedded. Ultrathin sections were contrasted using 5% uranyl acetate and 1% lead citrate for observation through transmission electron microscopy. The oil with the highest larvicidal efficiency was found to be nerolidol, followed by farnesol, p-cymene, carvacrol, thymol and dihydrojasmone, with an LC₅₀ of 11, 21, 23, 40, 45 and 66 µg/mL, respectively. The treated Ae. aegypti larvae caused alteration to the tegument or internal portions of larvae. The present study demonstrated which of these oils—dihydrojasmone, farnesol, thymol, p-cymene, carvacrol and nerolidol—have effective larvicidal activity. Full article

Chalcones are direct precursors in the biosynthesis of flavonoids. They have an α,β-unsaturated carbonyl system which gives them broad biological properties. Among the biological properties exerted by chalcones, their ability to suppress tumors stands out, in addition to their low toxicity. In this perspective, the present work explores the role of natural and synthetic chalcones and their anticancer activity in vitro reported in the last four years from 2019 to 2023. Moreover, we carried out a partial least square (PLS) analysis of the biologic data reported for colon adenocarcinoma lineage HCT-116. Information was obtained from the Web of Science database. Our in silico analysis identified that the presence of polar radicals such as hydroxyl and methoxyl contributed to the anticancer activity of chalcones derivatives. We hope that the data presented in this work will help researchers to develop effective drugs to inhibit colon adenocarcinoma in future works. Full article